/*
- * linux/drivers/block/elevator.c
- *
* Block device elevator/IO-scheduler.
*
* Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE
struct request *elv_latter_request(request_queue_t *q, struct request *rq)
{
- struct list_head *next;
-
elevator_t *e = q->elevator;
if (e->ops->elevator_latter_req_fn)
return e->ops->elevator_latter_req_fn(q, rq);
-
- next = rq->queuelist.next;
- if (next != &q->queue_head && next != &rq->queuelist)
- return list_entry_rq(next);
-
return NULL;
}
struct request *elv_former_request(request_queue_t *q, struct request *rq)
{
- struct list_head *prev;
-
elevator_t *e = q->elevator;
if (e->ops->elevator_former_req_fn)
return e->ops->elevator_former_req_fn(q, rq);
-
- prev = rq->queuelist.prev;
- if (prev != &q->queue_head && prev != &rq->queuelist)
- return list_entry_rq(prev);
-
return NULL;
}
ssize_t elv_iosched_store(request_queue_t *q, const char *name, size_t count)
{
char elevator_name[ELV_NAME_MAX];
+ size_t len;
struct elevator_type *e;
- memset(elevator_name, 0, sizeof(elevator_name));
- strncpy(elevator_name, name, sizeof(elevator_name));
+ elevator_name[sizeof(elevator_name) - 1] = '\0';
+ strncpy(elevator_name, name, sizeof(elevator_name) - 1);
+ len = strlen(elevator_name);
- if (elevator_name[strlen(elevator_name) - 1] == '\n')
- elevator_name[strlen(elevator_name) - 1] = '\0';
+ if (len && elevator_name[len - 1] == '\n')
+ elevator_name[len - 1] = '\0';
e = elevator_get(elevator_name);
if (!e) {